you can use RF Hybrid modules (about 903 mhz) connect each tip-ups on a micro-controlor port and the hybrid (Tx)circuit will send different data (depending on witch pop-up is activated) to the remote hybrid (Rx) who will notifie things depending upon the case.... this can be used a far as 1/4 miles (open area) with small antennas. It's very easy to use and adapt to any micro-controlor